merge dockerfiles

Signed-off-by: LEI WANG <ssst0n3@gmail.com>

templates/ubuntu.Dockerfile

@@ -2,13 +2,18 @@ FROM {{ .Image }}
 
 USER root
 
+{{ if le .Release.VersionID "14.04" }}
+# restore initctl
+RUN rm /sbin/initctl && dpkg-divert --rename --remove /sbin/initctl
+# setup ttyS0
+RUN cp /etc/init/tty1.conf /etc/init/ttyS0.conf && sed -i s/tty1/ttyS0/g /etc/init/ttyS0.conf
+{{ end }}
+
 RUN ARCH="$([ "$(uname -m)" = "x86_64" ] && echo amd64 || echo arm64)"; \
   apt-get update && \
   DEBIAN_FRONTEND=noninteractive apt-get -y install --no-install-recommends \
   linux-image-virtual \
   initramfs-tools \
-  systemd-sysv \
-  systemd \
 {{- if .Grub }}
   grub-common \
   grub2-common \
@@ -21,18 +26,29 @@ RUN ARCH="$([ "$(uname -m)" = "x86_64" ] && echo amd64 || echo arm64)"; \
 {{- end }}
   dbus \
   isc-dhcp-client \
-  iproute2 \
   iputils-ping && \
   find /boot -type l -exec rm {} \;
 
+{{ if gt .Release.VersionID "14.04" }}
+RUN ARCH="$([ "$(uname -m)" = "x86_64" ] && echo amd64 || echo arm64)"; \
+  apt-get update && \
+  DEBIAN_FRONTEND=noninteractive apt-get -y install --no-install-recommends \
+  iproute2 \
+{{ end }}
+
 {{ if gt .Release.VersionID "16.04" }}
+RUN ARCH="$([ "$(uname -m)" = "x86_64" ] && echo amd64 || echo arm64)"; \
+  apt-get update && \
+  DEBIAN_FRONTEND=noninteractive apt-get -y install --no-install-recommends \
+  systemd-sysv \
+  systemd
 RUN systemctl preset-all
 {{ end }}
 
 {{ if .Password }}RUN echo "root:{{ .Password }}" | chpasswd {{ end }}
 
 {{ if eq .NetworkManager "netplan" }}
-RUN apt install -y netplan.io
+RUN apt-get install -y netplan.io
 RUN mkdir -p /etc/netplan && printf '\
 network:\n\
   version: 2\n\
@@ -47,7 +63,7 @@ network:\n\
         - 8.8.4.4\n\
 ' > /etc/netplan/00-netcfg.yaml
 {{ else if eq .NetworkManager "ifupdown"}}
-RUN if [ -z "$(apt-cache madison ifupdown-ng 2> /dev/nul)" ]; then apt install -y ifupdown; else apt install -y ifupdown-ng; fi
+RUN if [ -z "$(apt-cache madison ifupdown-ng 2> /dev/nul)" ]; then apt-get install -y ifupdown; else apt-get install -y ifupdown-ng; fi
 RUN mkdir -p /etc/network && printf '\
 auto eth0\n\
 allow-hotplug eth0\n\